As a method for purifying a therapeutic protein, which is well-known as a biopharmaceutical, JP-A 2001-70827 (paragraph number 0002) discloses a method using centrifugation, filtration by a filter, gel chromatography or the like; and JP-A 2011-6489 (claims) discloses a method using affinity chromatography.
Then, a purifying process may include virus inactivation, with which a therapeutic protein is adulterated.
As a method for virus inactivation, JP-A 2003-2896 and JP-A 2009-263231 disclose a method for the contact-processing of a therapeutic protein in a low-pH aqueous solution (paragraph number 0032 of JP-A 2003-2896; and claims of JP-A 2009-263231).
When virus inactivation treatment is conducted on a therapeutic protein, sampling is necessary in order to check that viruses in the therapeutic protein are inactivated. Further, JP-A 2009-263231 indicates in Examples (Tables 1 to 6) the relationship between pH and the virus inactivating efficiency.
In order to prevent therapeutic proteins from being contaminated, it is desired to automate such inactivation and sampling in a closed system.